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                小P的烦恼                </h1>
                <p>时间限制：20s&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;  空间限制：512MB</p>			</div>
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                                <h3>题目描述</h3><p><div style="text-indent: 21pt"><span style="font-size: medium">小P最近遇上了大麻烦，他的高等代数挂科了。于是他只好找高代老师求情。善良的高代老师答应不挂他，但是要求小P帮助他一起解决一个难题。</span></div>
<div style="text-indent: 21pt"><span style="font-size: medium">问题是这样的，高代老师近期要组织班上同学一起去漂流，漂流可以看做是在一张n个点m条边的有向无环图上进行的，点编号从0到n-1，表示景点；边是连接各景点的一定长度的河道。同时，定义编号为s是起点而t是终点。我们不妨把从s点到t点不论走什么样的路径都需要经过的边称为桥，这些桥由于地势险要所以是危险的。现在高代老师有两条长度为l的安全绳，他希望用这两条安全绳覆盖尽可能长的桥，使得他们通过的桥的长度之和尽量短。</span></div>
<div style="text-indent: 21pt"></div></p><hr/><h3>输入格式</h3><p><div style="text-indent: 21pt"><span style="font-size: medium">本题包含多组数据，第一行是一个数T(T&lt;=5)表示数据组数，对于每组数据，第一行是5个数，n,m,s,t,l。</span></div>
<div style="text-indent: 21pt"><span style="font-size: medium">以下m行，每行包括三个数si,ti,pi,表示从si到ti有一条长度为pi的单向边。</span></div>
<div></div></p><hr/><h3>输出格式</h3><p><div>&nbsp;</div>
<div style="text-indent: 21pt"><span style="font-size: medium">对于每组数据，输出一行，包括一个整数，为最优情况下通过的桥的长度之和。如果不存在从s到t的路径，请输出-1。</span></div>
<div></div></p><hr/><h3>样例输入</h3><pre>
1


8 9 0 7 7
0 4 1
0 1 10
1 2 9
4 2 2
2 5 8
4 3 3
5 6 6
5 6 7
6 7 5
</pre><hr/><h3>样例输出</h3><pre>1
</pre><hr/><h3>提示</h3><p><p><span style="font-size: medium">对于100%的数据,n&lt;=100000,m&lt;=200000,0&lt;=s,t,si,ti&lt;n, l&lt;=10^9,pi&lt;=100<br />
</span></p></p><hr/><h3>题目来源</h3><p>没有写明来源</p>
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